alking down an aisle at Whole Foods, “DHA” and
“omega-3” labels adorn various food items including milk, eggs, nuts, flaxseeds and oils. What is this
mystery substance, and why are grocery stores promoting it?
Docosahexaenoic acid (DHA) is an omega-3 fatty acid
critical for optimal brain health and function at the prenatal
stage of development as well as later in life.1 Despite its importance as a key hormone in brain function, DHA levels are low
in America. This national deficiency has led to the production
of DHA-fortified baby formulas and prenatal vitamins.
Dr. Carol Cheatham, a developmental cognitive neuroscientist at UNC-Chapel Hill’s Nutrition Research Institute,
is working to understand the implications of this nationwide
DHA deficiency. Specifically, her research focuses on the process and efficacy of DHA transfer from mother to child via
both the placenta and breast milk.3
Although physicians have long touted the advantages
of breastfeeding, Dr. Cheatham’s research shows how, without
proper maternal diet, breastfeeding may not always provide
some important nutrients. The explanation lies in the genotype of the mother. Seven percent of US women are genetically unable to synthesize DHA.3 Consequently, these women
have less DHA in their blood plasma during pregnancy, resulting in a lower amount of DHA supplied to the fetus during its

brain development phase and after birth.
“I don’t want women to
think that breast milk is bad; I
want to encourage breastfeeding. But if certain women are part
of this seven percent, then they
will have to eat plenty of DHA,” Dr.
Cheatham said.
DHA-fortified formula is
commercially available, but clinical trials have not been able to
prove that supplemental DHA has
the same benefits as natural DHA;
Dr. Carol Cheatham
in fact, fewer than 40 percent of
trials have found that it does.
Moreover, physicians in the United States do not commonly test for reduced DHA levels in their patients.3 As a result,
it is unlikely that a woman in America will know if she is part
of the seven percent of females who cannot synthesize DHA.
One way to correct a DHA deficiency is by reducing omega-6
intake and increasing omega-3 intake. Dr. Cheatham recommends that all pregnant women, regardless of their genotype,
obtain exogenous sources of DHA and other omega-3 acids
Figure 1. In one of Dr. Cheatham’s
labs, a six month old named Lincoln
participates in a unique study. His
scalp covered in 128 electrically
sensitive sponge cups, Lincoln sits
quietly on his mother’s lap, watching a screen of blinking images.
As Lincoln observes each passing
image of a toy, the sensors create a graphical representation
of his brain activity. Upon seeing
new toys, Lincoln’s brain activity increases. When a familiar toy
appears, however, the brain does
not expend its energy to process
the familiar toy again. Photo by Jon
Lakey, Salisbury Post.